Protective effects and mechanisms of OSR on primary cultured hippocampus neurons subjected to anoxic injury in neonatal rat / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the protective effects of oxysophoridine (OSR) on primary cultured hippocampus neurons subjected to anoxia injury in neonatal rats and its mechanism.</p><p><b>METHOD</b>The model of anoxia injury of hippocampus neurons in neonatal rats were primarily cultured in vitro by physical oxygen deficiency using glucose-free culture fluid. The survival rate of neurons, the leaking rate of lactate dehydrogenase (LDH), the intracellular contents of malondialdehyde (MDA) and nitric oxide (NO), the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and nitric oxide synthase (NOS) were measured. The intracellular free calcium concentration ([Ca2+]i) in hippocampus neurons were detected with Ca(2+)-sensitive dual wavelength fluorescence spectrophotometer.</p><p><b>RESULT</b>Neuron death occurred in the anoxia injury model group with increase of LDH leaking rate, the contents of NO, MDA, intracellular [Ca2+] and the elevated activity of NOS while decreased activities of SOD and GSH-PX. The hippocampus neurons subjected to anoxia injury were alleviated in OSR (0.625, 5, 10 microg x L(-1)) group.</p><p><b>CONCLUSION</b>OSR has significant protective effects on hippocampus neurons subjected to anoxic injury. The mechanism of its protective effect may relate to its reduction of calcium overload and against oxidation injury.</p>

Cloning, sequencing and expressing of microneme protein 1 partial gene in toxoplasma gondii ZS2 isolate / 中华预防医学杂志

<p><b>OBJECTIVE</b>To construct a recombinant prokaryotic expression vector (plasmid) containing microneme protein 1 (MIC1) partial gene in toxoplasma gondii (T. gondii) ZS2 isolate. The gene was expressed in varied Escherichia coli (E. coli) after sequencing.</p><p><b>METHODS</b>The gene fragment coding MIC 1 from the genomic DNA of T. gondii ZS2 isolate was amplified by polymerase chain reaction (PCR). The gene was inserted to a prokaryotic expression vector pWR450-1 by digesting with restriction enzymes and linking reaction. The positive clone was screened on LB plates containing ampicillin and identified by restrictive enzyme digestion, PCR amplification and sequence analysis. The recombinant plasmid was transferred into E. coli TG1, JM109 (DE3) and DH5 alpha, and was expressed under the induction of IPTG. The expression products were identified by SDS-PAGE. The MIC1 gene structure was analyzed and compared in homology with the gene sequence of RH isolate using computer software.</p><p><b>RESULTS</b>The recombinant plasmid pWR450-1/MIC1, after cloning from acquired 471 bp MIC1 gene fragment and amplified from the genome gene ZS2, was complete homologous to the sequence of RH isolate, reflecting its highly conservative. The gene could be expressed as fusion protein with 70,000 in varied E. coli.</p><p><b>CONCLUSION</b>Recombinant plasmid pWR450-MIC1 was successfully constructed and could be expressed in different strains of E. coli, laying a foundation for research on its structure and function.</p>